As a UH professor of anatomy and reproductive biology, Milton Diamond teaches neuroanatomy and sexology. But his international notoriety resulted from what he calls a simple search for evidence.

“Some people think there has to be something strange about me to study sex,” says Diamond, who directs the medical school’s Pacific Center for Sex and Society and lectures worldwide. “Personally, I wonder why more people aren’t studying sex. It’s so intrinsic to so many aspects of our lives.”

A graduate of Bronx High School of Science and college ROTC, Diamond pursued anatomy, endocrinology and experimental psychology at the University of Kansas. In 1967 colleagues asked him to help start UH’s John A. Burns School of Medicine. Diamond and his wife thought the islands would be a good place to raise their four daughters. He found it a good place to work—writing several books, developing PBS’s award-winning “Human Sexuality” series and contributing to the American Medical Association’s handbook on sexual problems.

A few years ago, Diamond’s investigation of what he calls the “John/Joan case” thrust him into the limelight. The 1960s case involved a 7-month-old twin whose penis was severely burned by the electrocautery instrument used during circumcision. The boy’s parents contacted psychologist John Money, a leader in the field of gender identity at Johns Hopkins University, who counseled them to raise their son as a girl. Money believed a child’s sexual identity is determined by the appearance of the genitals and the child’s upbringing. “It’s the nature/nurture debate,” says Diamond. “Nurture advocates believe that if you’re raised (figuratively) in a blue room you become a boy and in a pink room, a girl. The only problem is, that theory doesn’t work.”

The child underwent surgery to remove his testes and fashion female genitals. His parents were instructed to raise him unambiguously as a girl. In journal articles and a book, Money described behavior “so normally that of an active little girl and so clearly different by contrast from the boyish ways of her twin brother.” Time magazine reported the experiment “has apparently succeeded.” Skeptical, Diamond called for evidence in various publications.

The medical establishment embraced Money’s conclusions. Surgical reassignment of sex for a variety of reasons, including cases where the penis was considered too small (less than 2.5 centimeters), became standard medical practice. Diamond kept digging. In 1994 he contacted British Columbia psychiatrist Keith Sigmundson, in charge of John/Joan’s treatment under Money’s direction. Sigmundson knew the sex conversion hadn’t worked. Unaware of her history; Joan had refused to wear dresses, hated make-up and fought like a boy. She was banned from the girl’s restroom for standing to urinate. At 14, she decided to live as a male. Sigmundson hadn’t challenged Johns Hopkins. “He thought that if it wasn’t working, it was his fault,” Diamond says.

Sigmundson put Diamond in touch with John/Joan, by then a married man struggling with psychological scars. In 1997 they presented their evidence in an article on implications of sex reassignment in the Archives of Pediatrics and Adolescent Medicine. This time the medical establishment listened. Diamond addressed the American Academy of Pediatrics. “I expected them to throw rocks at me because I was basically telling them that what they’d been doing for the past 40 years was wrong,” he says. Instead, 30 seconds of stunned silence gave way to applause.

“If you change someone’s gender as an infant, you’re doing something fundamental to them. As they grow up they’re living with incongruities that don’t make any sense to them, and they have no way of dealing with their feelings.” Many contemplate suicide. Diamond says as many as 200 pediatric sex reassignments were taking place annually in the United States due to damaged or ambiguous genitals. About 1 child in every 2,000 is born with enough ambiguity that it’s externally noticeable. One in every 100 has hidden ambiguity—XXY or other sets of chromosomes or combinations of ovaries and testes. “Gonads produce hormones that affect the brain, and it’s our brains that tell us whether we’re male or female,” he says. “In most cases, there’s a physical reason why individuals might be unsure about their sex.”

Yet doctors must classify a child’s gender at birth. Diamond offers three guidelines—don’t do surgery based only on genital appearance; do follow-up studies on the success of sex-reassignment; eliminate secrecy. “Yes, it’s disturbing for someone to find out they have male chromosomes along with a vagina, but keeping them in the dark is disturbing, too. People could deal with the truth if told in the proper way and provided with counseling.”

Since exposing the failure of the John/Joan case, Diamond has received numerous international honors and been interviewed on national TV. He served as president of the International Academy of Sex Research, which encompasses physicians, psychologists, sociologists and other scientists. “You work for 40 years then you’re an overnight success,” he quips.